The Role of Black-Silicon Solar Cells in Making Solar Energy More Affordable

The National Renewable Energy Laboratory, a part of the United States Department of Energy, worked on how to produce black-silicon solar cells that is a step ahead of other discoveries. At just above 18 percent efficiency, these solar cells are unique which do not require any additional anti-reflection layers. As a result, they will help bring down the often substantial price tag associated with solar power.

Solar cells are typically expensive because they cost a lot to manufacture. They often need multiple anti-reflection layers, and each one increases the cost of the product. The cells developed by the NREL, however, are different. Their top layer was specifically created so that power can still be garnered from the product even though it is made from black silicon.

The individuals working on the project were also able to manipulate the solar cells so that their efficiency is better than anything that has been seen before. Researchers were able to figure out a way to create billions of tiny holes throughout the top layer of the silicon; these holes are even smaller than the light that shines on the cells, meaning that the wavelengths are not pushed back away from them. They are able to be utilized instead.

The National Renewable Energy Laboratory has research that backs up the fact that their nanostructures function at a higher level than any other anti-reflection layers, even those that are considered the top ones on the market. While they struggled in the past with solar cell efficiencies, that is no longer an issue. Their black-silicon solar cells are able to compete with any similar product out there, including those that result from the China manufacturing process.

To be successful, workers at the NREL had to figure out why a larger surface area negatively impacted how much electricity current could be harnessed. What they found was that something known as Auger recombination interfered with how many photons could be gathered on the majority of solar cells.

After understanding why Auger recombination happens, they figured out a way to overcome the process with shallower and lighter doping. The result is the creation of a black solar cell with an extremely high efficiency. Researchers want to take things a step further, however. They would like to raise the efficiency to more than 20 percent and get solar panel manufacturers to put more out on the market and in use.